In recent years, electric vehicles have achieved significant improvements in core technologies and have been gradually entering the stage of practical use and small scale industrialization.
The OBCM (on board charge module) is a key component of an electric vehicle and is an electronic device mounted on the electric vehicle for charging battery packs. The OBCM uses input wires to receive alternating current from the AC power grid, and outputs a high voltage direct current to charge the high voltage battery pack mounted in the electric vehicle. Moreover, the OBCM uses a communication port to maintain real-time interactive communications with a battery management system (BMS).
In the miniature trend, the space occupied by the printed wiring board assembly (a key component of the OBCM) in the heat-dissipating base is intended to be reduced as much as possible. As a result, the printed wiring board assembly may become so close to any surface of the heat-dissipating base, and a short circuit of the printed wiring board assembly may happen because current heat-dissipating bases are often designed as a ground member. Under a severe short circuit, the power conversion assembly may be totally damaged, resulting in a cost burden of the industry. The OBCM is mounted on the vehicle, so it often faces different challenging environments such as high temperature, high humidity, strong vibrations, and dramatic changes of the environment temperature. Therefore, how to avoid the short circuit of the power conversion assembly and the heat-dissipating base due to collisions or vibrations in the vehicles becomes an important issue.